The hidden kingdom of microscopic alien organisms shapes the universe as much as galaxies, stars, and planets; new discoveries reveal how bacteria, viruses, and other micro-organisms built life on Earth and influence humanity's future in the cosmos.

Galaxies are locked in continual combat across the universe, and our own Milky Way will face its biggest opponent ever, the Andromeda Galaxy, in a titanic and deadly struggle that could create a new and unrecognizable super galaxy.